by EBSCO Medical Review Board


Hypothyroidism is when the thyroid gland does not make enough hormones. The thyroid is a butterfly-shaped gland in the front of the neck. It makes hormones that regulate growth, brain development, and metabolism. Early treatment can improve outcomes.

The Thyroid Gland
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In most babies, the cause is not known. In others, causes may be due to:

  • Certain genes
  • A temporary shortage of thyroid hormones in babies born very early
  • Abnormal development of the thyroid gland
  • A defect in producing thyroid hormones

Risk Factors

The risk of this problem is higher in people who have other family members who have had it.

Other things that may raise the risk in the mother during pregnancy are:

  • Taking certain medicines, such as radioactive iodine therapy
  • Autoimmune thyroid disease
  • Too much iodine


Problems may be:

  • Poor feeding and problems gaining weight
  • Sleeping more than usual
  • A hoarse cry
  • Problems passing stool
  • A puffy face
  • Soft spots on the head
  • A large, thick tongue
  • Floppy muscles
  • Yellowing of the skin
  • Swollen belly
  • Problems breathing
  • Poor growth


Most infants are screened at birth. Blood tests are done to check thyroid levels.


This condition can lead to growth and development problems. Early treatment can improve outcomes.

Medicine will be given to replace missing hormones. Hormone levels will need to be checked often to keep them at a normal level.


There are no known guidelines to prevent this health problem.


American Thyroid Association 

Genetics Home Reference 


Health Canada 

Thyroid Foundation of Canada 


Congenital hypothyroidism. EBSCO DynaMed website. Available at: Accessed February 10, 2021.

Congenital hypothyroidism in infants. Healthy Children—American Academy of Pediatrics website. Available at: Accessed February 10, 2021.

Jonklaas J, Bianco AC, et al; American Thyroid Association Task Force on Thyroid Hormone Replacement. Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacement. Thyroid. 2014 Dec;24(12):1670- 1751.

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